Twelve leading universities in the US and Europe have joined an internet platform created by two Stanford University scientists which provides free online access to classes designed by academics at elite institutions.

The move, announced on Tuesday, marks a significant expansion of online university teaching. Observers say it heralds a shakeup of the classic lecture theatre model.

The new participants in Coursera, which combines online lectures with assignments to be submitted, include the California Institute of Technology, Johns Hopkins University, and University of California, San Francisco in the US, as well as Edinburgh University and the Swiss Federal Institute of Technology of Lausanne.

Caltech and the University of Pennsylvania have also announced a combined $3.7m (£2.4m) investment in Coursera.

Coursera already offers classes from Princeton, the University of Michigan, Stanford, University of California, Berkeley and the University of Pennsylvania.

The 12 universities joining the platform will offer dozens of new courses in the arts, computer science, health, mathematics, history, literature and other disciplines.

The classes offered by Coursera do not count as credit towards degrees at the universities involved, but online students receive certificates for completing their studies.

Andrew Ng, the Stanford academic who co-founded Coursera with Daphne Koller, said the move gave students "greater access than ever before to the world's foremost subject-matter experts".

Koller said: "We're fortunate to have the support of these highly respected academic institutions as we move toward our shared goal of providing a high-quality education to everyone around the world."

Many universities already offer online lectures and some – notably the Open University – offer qualifications through distance learning. But observers say the rise of Coursera and similar online offerings marks a shift in the balance of power in higher education.

Mike Boxall, of the management consultancy PA Consulting, compared the development to the changes that have swept the media and music industry. "The interesting thing is that it effectively marks the provision of knowledge as a free good, which accords with young people's expectations. Now you've got the industry saying, we have to protect our offer – that offer is not the key to the library door – they have to provide something around that, the ability to use and interact with that knowledge."

The growth in online learning is likely to push universities towards greater emphasis on one-to-one tuition and other interaction with students, Boxall said. "What does that mean for 500-seat lecture theatres? It's amazing that universities are still building big lecture theatres – there's a huge wave of building across the university world. They're not rethinking that environment."

It is also a sign of the untapped demand for higher education. In recent years, there has been keen interest from venture capital in private for-profit higher education providers.

A consortium including Goldman Sachs owns the US private HE provider Education Management Corporation, while Montagu private equity recently acquired the College of Law, the UK's biggest law school, for £200m.

Boxall said: "There is huge latent demand. Public higher education is under pressure but the bigger market for learning is just vast."

Jeff Haywood, vice-principal at Edinburgh University, said his institution was adopting a breakeven model. The platform serves as a shop window for universities; a free course with no entry qualifications offers students a way of sampling a traditional university education. It also offers the universities a chance to innovate, Haywood said. "There's an ability to experiment at a scale that we can't do on campus – you can't put together a class of 20,000 students on campus. If we're able to get some confidence that we can do automated large-scale assessment, on computers, we may do more of that and release our academic team to do higher value-added teaching."

An internet-based model which can pick the best courses from around the world puts greater pressure on universities to be distinctive; one of the courses Edinburgh will offer is in artificial intelligence, for which it has an international reputation.

Dr Wendy Piatt, director general of the Russell Group, which represents leading universities including Oxbridge and Edinburgh, said: "Online technologies provide huge opportunities for the dissemination of knowledge, and our universities are continuing to take advantage by, for example, putting lectures online through iTunes U and YouTube, or by making much of our research open access. Russell Group universities have always been at the forefront of online innovations, and we are keen to exploit this further."